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However, I believe that we need a more >>> generalised concept for CoCo pre-decrypted allocators in the kernel. >>> >> There is a talk at LPC in the networking track about this [2]. This is >> exactly the type of discussion that I was hoping to have there. >> >> Besides the issues mentioned in this thread we've also found that a lot >> of overhead can come only from swiotlb allocations when running many queues. >> >> I will add information about this series in my talk. Hopefully I will also >> have time to add some numbers for comparison. >> >> Sorry for the late reply but I spotted this thread only now by >> accident. >> >> [1] https://lore.kernel.org/all/20260325192352.437608-3-jiri@resnulli.us/ >> [2] https://lpc.events/event/20/contributions/2464 > > Thank you for the feedback and links. > > Do you have some code describing [2] ? > Not yet I will send a link once I push it somewhere. But the idea is simple: a driver side alternative data-path which uses pre-allocated coherent DMA buffers. This doesn't make memcpy go away but eliminates the swiotlb all together and it reduces the DMA map/unmap overhead. > I just sent a cleaned-up v2 of my previous series, if you want to try > it please use the latter. > Thanks! Had a quick lock and wrote some comments. Thanks, Dragos